Triplet energy transfer and cis-trans isomerization in 3-phenyl-2-propenyloxybenzophenone

In this report, photochemical behavior of 2-(3-phenyl-trans-2-propenyloxy)benzophenone and 2-(3-phenyl-cis-2-propenyloxy)benzophenone is discussed. In contrast to allyl and propargyl ethers of 2-hydroxybenzophenone that were photoactive at 330 nm leading to the formation of 2,3-disubstitutedbenzofuranols, 2-(3-phenyl-trans-2-propenyl oxy)benzophenone and 2-(3-phenyl-cis-2-propenyloxy) benzophenone under these conditions led to photoisomerisation and resulted in the formation of a mixture of cis and trans isomers in photostationary equilibrium, due to intramolecular energy transfer.